1. Field of the Invention
In one embodiment, the invention herein pertains to the field of plant growth regulation.
In another embodiment, this invention pertains to the use of plant growth regulator compositions containing certain 3-[(naphthyl, or substituted-phenyl)imino]-phthalides, among which are novel compounds per se.
2. Description of the Prior Art
Within the prior art pertinent to this invention is disclosed a broad generic class of compounds encompassing species pertinent to the present invention. These compounds, prepared by known methods, are variously described generically as 3-substituted imino phthalides or N-(substituted) phthalisoimides. See, e.g., an article by W. R. Roderick et al in J. Org. Chem. 28, 2018-24 (1963) and in the same journal an article by R. K. Howe at 38, 4164-67 (1973).
Although the prior art discloses numerous imino phthalides having no substituents or a variety of substituents on the phenyl moiety of the aniline residue, including halo, methyl, alkoxy and dimethylaminophenyl radicals, to applicants' knowledge, the compounds 3-[(o-chloro-m-trifluoromethylphenyl)imino]-phthalide and 3-[(o,m-dimethoxyphenyl)imino]-phthalide are novel and unobvious.
The prior art appears silent with respect to any suggested use of imino phthalides as plant growth regulators. In fact, applicants have discovered that certain of the known imino phthalides are inactive as plant growth regulators. For example, the unsubstituted phenyl imino phthalide and those phthalides substituted with p-chlorophenyl, p-methoxyphenyl, o-ethoxyphenyl and dimethylaminophenyl radicals are all inactive. Hence, without guidance from the prior art, applicants have found that certain imino phthalides are effective plant growth regulators, and further, with respect to those species having halogen or alkoxy substituents, the position of these radicals on the phenyl ring is critical.
Other prior art related to the present invention in a general sense includes isomaleimides disclosed in U.S. Pat. Nos. 2,995,577 and 3,035,065, to C. K. Sauers et al and other compounds described as substituted anilino phthalides as disclosed in U.S. Pat. No. 2,945,865 to D. D. Wheeler et al. However, none of the Sauers et al or Wheeler et al compounds are within the scope of the invention disclosed and claimed herein.